Southern California -- this just in

San Onofre months from restarting reactors

September 12, 2012 | 6:01
pm

The darkened San Onofre power plant will not restart even one of its two reactors for months, the head of the U.S. Nuclear Regulatory Commission said Wednesday.

In the meantime, anti-nuclear advocates stepped up pressure to keep the plant shut down, with the release of an analysis showing that the issues with San Onofre’s steam generators are among the worst in the industry.

The plant has been shuttered since Jan. 31, when a tube in one of the plant's newly replaced steam generators leaked, releasing a small amount of radioactive steam, and leading to the discovery that hundreds of other tubes were wearing out more rapidly than expected.

NRC Chairwoman Allison Macfarlane said at a U.S. Senate committee hearing on nuclear safety that Southern California Edison, the operator of the troubled nuclear plant, has told the agency it plans to submit an analysis of the problems and a restart plan for one of the plant’s two reactors, Unit 2, by the end of the first week in October.

Once that happens, she said, NRC staff will review the plan in a process that “will be longer than days and weeks –- it will be on the order of months.”

Edison has no immediate plans to submit a restart plan for the second reactor, Unit 3, which had more tubes with damage overall and more of a particularly unusual type of damage caused by tubes rubbing against other tubes.

The company has said that unit may not be able to fire up again without extensive repairs and has announced plans to remove fuel from the reactor.

Sen. Barbara Boxer (D-Calif.) questioned NRC commissioners at the hearing on their plans for San Onofre and suggested making regulatory changes that would require more extensive review of future projects, such as the costly steam generator replacement.

An initial NRC review of the issues blamed faulty computer modeling by steam generator manufacturer Mitsubishi Heavy Industries for the problems, but some have argued that the problems could have been avoided if design changes in the new steam generators had received a full NRC review.

NRC officials have said that Edison informed them of the design changes, but the company was not required to go through a license amendment process.

"We already know that they didn't have to get a new license to make a structural change, and we already know what happened," Boxer said. "It was terrible for the people in the community, it was terrible for the utility, and we still don't know exactly why this occurred."

Also Wednesday, the anti-nuclear group Committee to Bridge the Gap released a report with data compiled from steam generator tube inspection reports submitted to the NRC by all nuclear plants with similar replacement steam generators. The NRC does not compile the tube wear data in a central location, and the Electric Power Research Institute, which maintains a database of information reported by the utilities, says its data is proprietary.

San Onofre's units, which had been operating for about one and two years respectively, had 1,806 and 1,595 tubes with some degree of wear.

The group's analysis showed only one other plant, St. Lucie Nuclear Power Plant in Florida, with a unit that had comparable levels of tube wear to either of San Onofre's units. The median number of tubes with wear at other plants with newly replaced steam generators was four.

Another plant that showed severe tube wear in its replacement steam generators, Oconee Nuclear Station in South Carolina, was not included in the analysis because its equipment is one of a small number in the country with a completely different design.

“The conclusion is clear: San Onofre Unit 2 and Unit 3 are both very ill nuclear plants.… They are far, far outside the norm of national experience. And Unit 2 cannot be said to be acceptable for restart, any more than Unit 3,” the report's authors wrote.

NRC spokesman Victor Dricks said the agency had not had a chance to review the report Wednesday.

Edison spokeswoman Jennifer Manfre said the company had not unable to review the data in the report for accuracy, but called its presentation of the information misleading.

"We do have significant challenges at the plant, we do have tube wear issues, we're not denying that," she said. "But those numbers don't make any sense in and of themselves."

Manfre said that nuclear plants are built with extra tubes, with the expectation that tubes will be taken out of service due to wear, and San Onofre is well within the limits for the number of tubes that can be plugged. The more concerning issue, she said, was the tube-to-tube wear in Unit 3.